Celadon (Qīngcí 青瓷)|Qīngcí 青瓷 (Celadon)

Ellen HUANG

Amphora with dragon-head handles, made in the ninth century (Tang dynasty) in Changsha, Hunan Province. Ninth century (Tang dynasty). Stoneware with celadon glaze. Shown at the museum in Wang-ch’eng Park, Luoyang, Henan Province. Chinese communication with the cultures of western Asia and the Mediterranean is clearly documented by the addition of many foreign shapes to the Chinese ceramic repertoire. Amphoras, along with many other vessels, were carried over the Silk Roads, and their shapes were adapted with vigor and style by Tang potters. PHOTO AND CAPTION BY JOAN LEBOLD COHEN.

Celadon wares—ceramics with a green or blue-green glaze—are among the oldest glazed ceramics; they during the Shang dynasty (1766–1045 BCE). The green color results from a chemical reaction to small amounts of iron and titanium oxide in the glaze during firing in a kiln.

Celadon is the term for a wide range of ceramics with a pale green or blue-green glaze. The origin of celadon can be traced to the first glazed ceramic objects, which appeared during the Shang dynasty (1766–1045 BCE). The dispersal of celadon across the world indicates a global culture of ceramics that dates to before the era of blue-and-white ware’s dominance in the fourteenth through eighteenth centuries. Indeed, celadon’s global tracks are evidence of the Silk Roads and maritime trade routes linking China with the rest of the world.

Chemically, celadon’s greenish tint results from small amounts of iron and titanium oxide fired in a reducing atmosphere (a kiln atmosphere with a high level of carbon monoxide). Because of the difficulty of maintaining the reducing atmosphere in a kiln during firing, and thus maintaining the chemical reaction, celadon glazes also contain olive and yellow colors.

Conceptually, ancient celadon wares stand in contrast to the class of ceramics known as “porcelain,” a distinction based on body composition, firing temperature range, and degree of vitrification. The term porcelain technically connotes use of petuntse (a form of feldspar occurring only in China) and kaolin, which is a fine, white clay. The combination of these two materials made for a higher firing range. Porcelain stone was first utilized in ceramic making during the tenth century, when potters extracted the raw material in southern China at the porcelain center of Jingdezhen, Jiangxi Province. Porcelain rose in prominence, and the wares were more produced prolific after the late fourteenth century due to the official patronage of Jingdezhen porcelain by the Mongol rulers of the Yuan dynasty (1279–1368), who set up an official administrative unit to govern porcelain one year before they conquered all of China. By contrast, ancient celadon encompasses the stonewares that dominated production before the rise of porcelain production in the tenth century.

Development

The first ceramic glazes appeared in China during the Shang dynasty. The bodies of glazed ceramics were high fired, meaning that their firing temperature was around 1,200° C. In general, they were used mostly in ritual ceremonies. By the eastern Han dynasty (206 BCE–220 CE) the centers of celadon production were located primarily in modern-day Zhejiang and Jiangsu provinces in the lower Yangzi (Chang) River valley. The celadons produced during this time were also fired at around 1,200° C. Zhejiang and Jiangsu provinces correspond roughly with the territories under the control of the Yue and Wu states, thereby explaining the common association of the term Yue ware with types of ancient celadon. During the third and fourth centuries celadon production spread to Jiangsu, Hubei, Hunan, and Jiangxi provinces. Celadons were produced in southern and northern kilns from the seventh century onward. Their main period of development occurred between 220 CE and 618 CE, encompassing the North and South Dynasties period (220–589 CE) and the Sui dynasty (589–618 CE). Technical development of ancient celadon production culminated during the Tang dynasty (618–907 CE), when they were fired in kilns in the region known then as “Yuezhou” (present-day southern Zhejiang Province). The eighth century brought a resurgence of the greenwares of the Yue kilns, whose term was revived from five hundred years earlier, when it was first used during the Han dynasty. Celadons were the dominant type of wares produced until the late fourteenth century, when they were surpassed by the growing demand for white-bodied porcelains with white-blue glaze made in Jingdezhen, a southern kiln site. This change was also marked by the rise in prominence of blue-and-white wares and a shift in porcelain production centers from the northern kiln sites to southern kiln sites. The Northern Song dynasty (960–1126) brought an increased production of celadon referred to as “Ru ware” and “Guan ware” at kiln sites. After the capital moved to Hangzhou in southern China, celadons—known as “Longquan wares”—were produced at the Longquan kilns, also in southern Zhejiang Province near present-day Wenzhou city. The production of blue-green, thickly glazed, simply shaped celadon stonewares in Longquan County marked another notable point in celadon history.

History of Terminology

In Chinese-language texts celadon wares are known simply as “greenware,” demonstrating the crucial place of color in celadon’s definition. The comprehensive Chinese-language technical guide to porcelain, entitled Records of Jingdezhen Pottery (Jingdezhen Taolu), dating to the turn of the nineteenth century, refers to celadon wares using the terms for their glaze color, qing and qingci. Translated directly, these two terms mean “greenware.” The Western derivation of the term celadon may have begun in 1171 with a corruption of the name of the sultan Saladin, who made a gift of such celadon wares to the sultan of Damascus, or with the seventeenth-century French play written by Honore Darfe, which featured the shepherd Celadon who wore a greenish-gray cloak. Thus, in Western etymological terms, no technical description of the term celadon exists. Rather, celadon is simply a term whose history comprises descriptive usages.

Ancient celadon has been praised by Chinese writers and collectors in many ways, variously compared with the color of jade or clouds or the sound of light rain. During the Tang dynasty the revival of Yue kilns in southern Zhejiang Province resulted in part from official patronage of celadon wares by the Yue royal families and from the growing popularity of tea drinking as an art and cultural form in China, as well as among other East Asian places. In this cultural context an important document detailing the aesthetics and intricacies of tea drinking reveals the high value of Yue celadon wares at the time. The document, Classic of Tea (Chajing), written by Lu Yu (733–805 CE), was the first monograph on tea ever written. It comprised ten chapters and praised Yue porcelain for resembling jade and ice. The green color of Yue porcelain, according to Lu Yu, enhanced the green color of the tea itself. About a hundred years later, another poem, written by Xu Yin, a Tang dynasty poet and official active during the late ninth and early tenth centuries, lauded the ability of celadons to enhance the experience of drinking tea. The title of this poem refers to celadons as “secret color” (mise):

The Secret-Colored Bowl as Given
to the Emperor

Newly glazed in auspicious jade-like colors,

The finished bowl was first given to my lord.

Skillfully molded like a clear moon dyed with
spring water,

Deftly rotated like thin ice holding green clouds,

Like a moss-covered ancient bronze mirror
present at this occasion,

A tender, dew moistened lotus leaf parted from
the river’s edge,

With Zhongshan bamboo-leaf wine so recently
brewed,

I am weak and unable to withstand such an
experience! (Mino and Tsiang 1986, 13)

Evidently, as this poem shows, literati during this period appreciated celadons and compared them with ice, clouds, and jade. The term mise (secret color) ware originated during the Wu Yue state of the Five Dynasties period (907–960 CE). According to the Jingdezhen Taolu (Records of Jingdezhen Pottery), production of secret-color ware began during the tenth century and ceased at the beginning of the Ming dynasty (1368–1644), and because it existed for specific use at the imperial palace, the ceramics acquired the term mise.

Technological Definition

The scientific and industrial revolution of the mid-nineteenth century produced new understandings of porcelain. Alexandre Brongniart, a French chemist writing in 1844 as director of the French national ceramic manufacturing center at Sevres, attributed to porcelain these distinctive characteristics: whiteness, translucency, hard paste, not to be scratched by steel, homogeneous, resonant, vitrified, and impermeable to water. In Brongniart’s studies ceramics consisted of three types: earthenware, stoneware, and porcelain. Celadon, according to these types, is stoneware. Stoneware, which dates to the Shang dynasty, was fired at temperatures ranging between 1,100° and 1,270° C. Stoneware has also been called “porcelaneous ware,” and it includes vitrified objects. By the Han dynasty glazes containing ash content gave rise to the color now subsumed in the definition of celadon, a stoneware of brownish-green or yellowish-green glazes. Also during the early western Han dynasty (206 BCE–220 CE) the word zi, an antecedent of the word ci (porcelain), was first used to refer to celadons, which were used in burial tombs of elites.

Twentieth-century scientific studies revealed a wide array of chemical elements in various celadon glazes, including calcium, magnesium, soda, phosphorus, titanium, aluminum, silica, and potassium. The degree of translucency or transparency depends on the interaction between the physical properties of light rays and their interaction with heterogeneities of the glaze at the surface and beneath the surface. Approximately 4–6 percent of incidental light rays are reflected and scattered at the outer surface of the glaze. Glazes with elements having a higher atomic number, such as lead, and having a higher mass weight, reflect more light. Glazes of such composition thus appear brighter than feldspathic (relating to or containing feldspar) or alkaline glazes.

The portions of incidental light rays that do pass through the surface are then affected by the internal structures in the glaze. Bubbles of 0.1 millimeter or smaller in the glaze produce specular reflection, just like the glaze surface. As a result, light bounces off each of the bubbles and produces the glaze’s brightness and luminosity. Undissolved quartz particles absorb light and make the glaze appear matte. Crystals in the glaze result from the long firing and slow cooling at high temperatures. When raw materials are not finely ground and are insufficiently mixed, chemical heterogeneity ensues and creates a chemical composition similar to the crystal. Fine crystals on the order of microns in the glaze refract and scatter the light, thus giving a translucent appearance to the glaze. A rough layer of crystals at times grows at the layer where the glaze touches the clay body, creating the optical effect of a white slip. This layer of white ground reacts with the light and creates internal reflection in the glaze. The combined effect of bubbles, quartz inclusions crystals, and white grounds adds a depth and a luster to celadon glazes that make them appear like jade or green feldspar.

Major Types of Ancient Celadon

There are six major classifications of celadon, one of which, Chai ware, survives today only as described in historical texts. The availability of local minerals was a big factor in the makeup and appearance of the various styles.

Yue Ware

Yue ware dominated the history of ancient celadon from the Han dynasty to the sixth century CE. Coming to prominence between the third and sixth centuries, the bodies of Yue ware were gray and dense with a thin layer of glazes. Yue ware experienced a revival during the Tang dynasty and was found in Iraq and Iran. Its glazes averaged about 0.2 millimeters and had a high calcium content—up to 60 percent. It was fired mostly in the dragon kilns popular in Zhejiang Province, which caused a rapid cooling cycle. Yue celadons are not as translucent and jade-like as later celadons.

Longquan Ware

Longquan celadons, made in a mountainous region in Zhejiang Province southwest of present-day Shanghai close to Fujian Province, were produced during the Southern Song dynasty (1127–1279) and probably are the best known of all celadon types. They are a translucent blue-green color and are often found in the shapes of bowls and jars. They were traded to places such as Southeast Asia, the Philippines, Africa, and the Near East between the twelfth and fourteenth centuries. Thicker than the earlier Yue celadon glazes, Longquan celadon glazes ranged from 0.4 millimeters to 1.7 millimeters thick, thus creating a more translucent visual effect than the earlier Yue celadons. Longquan wares contain small amounts of undissolved clay and quartz, indicating that the Longquan glazes are not as finely grained as Yue ware glazes.

Yaozhou Ware

During the Northern Song dynasty (960–1126) celadon wares known for their molded and incised decorations were produced in Shaanxi Province. They supplanted the white wares and black-glazed wares of the north. Their glaze was gray-green or olive-green, thinly laid over deeply carved or molded bodies. The thickness of the glaze ranged from 0.4 to 0.8 millimeters and was not as unctuous (smooth and greasy in texture or appearance) as that of Longquan wares. The presence of titanium in the raw materials available in the north was responsible for the olive-green hue of the glaze. The titanium increases the brown color when combined with iron in the glazes.

Ru Ware

Ru ware, another type of Northern Song celadon known for its opaque, unctuous blue glaze on often-undecorated bodies, appeared near the end of the eleventh century. It is extremely rare, with fewer than one hundred complete pieces preserved, mostly in the Percival David collection in London or in the National Palace Museum. Presumably fired for the imperial court, Ru ware was produced only between 1086 and 1106 and was immediately treasured during the twelfth century because of its short production period. Ru ware was probably ordered to replace Ding ware, whose rough, unglazed rim did not please the court. The Ru glaze is so thickly applied that it was likened to layers of fat in the Chinese-language connoisseur texts.

Guan Ware

Guan ware was produced during the Northern and Southern Song dynasties. The Southern Song Guan wares were produced for the imperial court, and thus the term guan refers to “official” ware. During the Southern Song dynasty the center of production
for Guan ware was right outside Hangzhou in Zhejiang Province, where the court reestablished its capital city after the conquest of the northern provinces by the Mongol Yuan dynasty. Guan glazes are often more than 1 millimeter thick, crackled, and opaque, and the bodies are dark-colored and thin. The bodies are granular because of the presence of find sand in the body composition. Guan wares have a dark mouth (rim) and dark foot, referred to literally as “iron foot” in Chinese-language texts. Modern examinations of Guan shards (pieces or fragments of a brittle substance) reveal that the glaze was often applied by potters in an average of four layers. The high lime content accounts for the crackle. Guan ware is often underfired at a temperature of 1,000° C.

Chai Ware

To date, no archaeological findings can confirm the actual existence of Chai celadon. However, numerous ceramic connoisseurship texts praise Chai ware for being “blue as sky, clear as mirror, thin as paper, and resonant as a musical stone” (Hayashiya and Hasebe 1996, 48). Qing dynasty (1644–1912) texts on ceramics note that Chai ceramics were produced for Emperor Chai Shizong (954–959). This elusive but poetically described celadon ware awaits more research, but its mention in texts demonstrates the aesthetic significance of celadon’s natural beauty.

Export History

The Tang dynasty was an exuberant period of Chinese artistry and foreign contact. Yue celadons were a large part of the export trade between China and Central Asia since the time of the Tang dynasty. Yue celadon wares dating to the ninth century have been found in Southeast Asia, Indonesia, Sri Lanka, the Persian Gulf, and Cairo. The early ninth century brought a large-scale oceangoing trade between the Persian Gulf and China, affecting the trade of celadon ceramics. The first countries to import and even improve upon celadon technology were Korea and Japan. Korea in particular was a major player in the production of celadon. In the eleventh century Korean potters substituted porcelain stone for body clay in their celadon glaze recipes and produced brilliant blue-green celadon wares. Excavated Longquan wares and Guan wares dating to the thirteenth century have been found in Japan and Korea, demonstrating the continued trade of celadon wares through the Yuan dynasty. Longquan wares made during the Song, Yuan, and Ming dynasties were exported to Japan and the Philippines, and the presence of such late greenware ceramics in Japanese museums reveals the widespread appreciation for the simplicity and elegance of celadon glazes.

Further Reading

Gompertz, G. St. G. M. (1958). Chinese celadon wares. London: Faber and Faber.

Hayashiya, S., & Hasebe, G. (1966). Chinese ceramics. (C. A. Pomeroy, Trans.). Rutland, VT, and Tokyo: Charles E. Tuttle.

Mino, Y., & Tsiang, K. (1986). Ice and green clouds: Traditions of Chinese celadon. Bloomington, IN: Indianapolis Museum of Art.

Tichane, R. (1999). Celadon blues. Iola, WI: Krause Publications.

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